<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>样式练习</title>
</head>
<body>
    <div class="div1">你好</div>
    <div class="circle-question">?</div>
    
    <style>
        .div1{
            width: 100px;
            height: 100px;
            background-color: beige;
            color: yellow;
        }
        .circle-question {
            width: 100px; /* 圆的宽度 */
            height: 100px; /* 圆的高度 */
            border-radius: 50%; /* 圆形效果 */
            border: 3px solid blue; /* 蓝色边框 */
            display: flex;
            justify-content: center; /* 水平居中 */
            align-items: center; /* 垂直居中 */
            font-size: 48px; /* 问号大小 */
            color: blue; /* 问号颜色 */
        }
    </style>
</body>

</html>